Chicago-latrobe 49416 Screw Machine Drill Bit 0.081in Hss

Product Description

The CHICAGO-LATROBE 49416 is a screw machine length drill bit designed for high-speed steel cutting in demanding production and maintenance environments. Built to Series 159 specifications under NAS 907 designation, this bit features a 135-degree split point and web-thinned geometry that reduces thrust and improves hole entry accuracy. At 0.081 inches in diameter (Wire Size 46), the stubby screw machine length provides added rigidity compared to jobber-length bits, making it well suited for close-tolerance drilling where deflection must be minimized. Licensed tradespeople and machining technicians working with ferrous metals rely on this geometry for consistent, repeatable results.

This drill bit is rated for primary use in cast iron and steel workpieces and is built to heavy-duty performance standards, making it appropriate for production drilling, maintenance repair, and tool-room applications. The coated high speed steel construction extends cutting life compared to uncoated HSS in repetitive drilling cycles. The straight-cylindrical shank accepts standard drill chucks, making this bit compatible with drill presses, CNC drilling heads, hand drills, and screw machine spindles. It is sold individually and is available in multiples of 12 per order.

Key Features

• 135-degree split point with web-thinned geometry reduces entry thrust and walking
• Screw machine (stub) length provides increased rigidity and reduced deflection over jobber-length equivalents
• Coated high speed steel construction for extended tool life in steel and cast iron
• Two-flute regular spiral design promotes efficient chip evacuation in through-hole drilling
• Diameter tolerance held to +0.0000 to -0.0005 inches for close-fit hole applications
• Meets NAS 907 and ISO standards for consistent dimensional conformance

Compatibility

Designed as an OEM-style replacement and standard production drill bit for use in cast iron and steel applications; the straight-cylindrical shank fits any standard drill chuck or screw machine spindle accepting a 0.081-inch shank diameter.

Installation Notes

This bit is installed and operated by machinists, tool-room technicians, and maintenance tradespeople using drill presses, hand drills, or CNC equipment. Secure the straight shank firmly in a keyed or keyless chuck before operation and confirm chuck runout is within acceptable limits to preserve the tight diameter tolerance. Do not exceed the recommended feed and speed parameters for the workpiece material to avoid premature cutting-edge breakdown. Inspect the split point for chipping or wear before each use and replace the bit if the point geometry is compromised.